Bedini Capacitive Discharge Chargers

[Ewhaz]

I just got batteries to test my self oscilating circuit with but something strange happened.

After about 15 mins or so my capacitor began to overheat on the charging side. It's a 450v 3.3 uf capacitor so it should be set properly and be well within range for the unit. I'm using a Neon bulb to trigger the scr so the voltage never gets much above 55 volts in the cap.

Any one have any idea how to keep this from happening?

[Jetijs]

Ewhaz, I don't know why your capacitor is behaving like this, but I also have a question that someone hopefully can answer. I am going to try the cap pulser setup, but instead a scr or neon I want to use a solid state relay, driven by a 555 timer. The relay is rated for switching up to 250V and 60A. What do you think about this?

[elias]

I have thought of this too

Ewhaz, I don't know why your capacitor is behaving like this, but I also have a question that someone hopefully can answer. I am going to try the cap pulser setup, but instead a scr or neon I want to use a solid state relay, driven by a 555 timer. The relay is rated for switching up to 250V and 60A. What do you think about this?

Yes, I thought of doing this too. Relays can make much better contacts and may produce better charging effects. Please tell us if you get better results.

[Aaron]

discharging caps

So how would you be able to trigger a capacitor to discharge using a neon bulb? If your cap is only 2V above you 12V batt so lets say 15V cap cause I cant find a 14V one. But your neon bulb is rated at 60V-120V wouldn’t your cap just get real hot because it would never get up to the voltage required to jump the gap in the bulb essentially destroying your cap! And whats the purpose of the SCR is the SCR going to the batt or is it on the SGG side? Iam not as electronically smart as much as most of you. An SCR is basically a diode with a set voltage trigger right? So would that be placed just before the bulb to prevent any Voltage form reversing back to the cap. Iam looking at purchasing a 180000 uf 15V cap but not sure how to oscillate it with the neon bulb any help appreciated!

If that question was for me, anytime I discharged only a few volts above the battery, it was using 60v caps and each cap was 30,000uf. I had about 6 of them in parallel for about 180,000uf. The discharge for this setup was by mechanical pulley triggering a copper sheet switch that I made. This is the setup that allowed my charging batteries continue to charge/climb for up to an hour after there was no more input from the caps. This makes for a good strong charge.

The only time I used a neon bulb to discharge was on very, very low capacitance caps like 1uf, 0.1uf, 0.01uf and the caps were like 600volts. The voltages on this low of capacitance rose to the neon trigger voltage pretty easy. This setup was charging batts with too much radiant...not enough current to really get the batteries in true charging mode. The voltage climbs but it is really a fluffy electrostatic charge.

I never had capacitors get hot in either situation.

[Ewhaz]

Well, the unit is switching at like 2khz at least so maybe it's just a matter of the frequency. As I said the cap is holding at 55 to 60V with this setup.

The 555 timer set up seems it would work closer to 14hz.. so thats a HUGE difference.

But there is one thing I noticed however. Despite the fact the Cap is holding at 55v the battery still only shows maybe a volt or two above charge. I'm sure the internal impedance of the battery might have something to do with this.

[splocal]

cap charging

If that question was for me, anytime I discharged only a few volts above the battery, it was using 60v caps and each cap was 30,000uf. I had about 6 of them in parallel for about 180,000uf.

I was hoping anyone with experience would respond so thank you Aaron. I know you have been involved with this work for some time! That is great news maybe I miss read your previous post I thought it was one cap at 180000 uf. 30000 uf caps are much easier to find. I have noticed that even with out the caps I sometimes have received a "fluffy" charge. voltage looks good but battery load is weak. Maybe I need to tune my SG better, I am definatly going to try the caps thanx again!

[Aaron]

big caps

I found most of these 30,000 uf caps on ebay. I paid about $6 each. If you want to get really high capacitance caps, you can probably find them at car stereo shops, they might be kind of spendy. Probably will save quite a bit just paralleling some 30k uf's.

[elias]

10,000uF capactors at 16v are rather cheap

I bought about ten 16v, 10,000uF rubycon capacitors while paying about 3$ for all of them. This is a cheap option too, if high voltage capacitors are not required.

[splocal]

Thanx for the tips That is much cheaper than the 30$ caps i saw. thanx again!

[Ewhaz]

Any place to get the 2n3584 transistor

Man this transistor must be in short supply around the world! Hardly ANY one carries it and they are either charging too much or out of stock! The company I ordered mine from have had my order on back order for over 2 months!

Does any one know where I can get this 2N3584 transistor from? It's like the Very last piece I'm waiting on in order to finish my charger! Thanks in advance.

Alternative: Any compatible transistors that can be used instead of this one, preferably one that is more available?

[ren]

Mouser Electronics - Electronic Component Distributor

has them in stock. Or google semiconductor supplies, there are a heap of online sites that will offer postage options.

[Ewhaz]

I'm going to repost my question here about the batteries, due to the fact that this circuit is not the SSG but rather the self oscilatting circuit with the capacitive discharge.

I spent the day running my system the other day, a total of 12 hours overall. Right off the bat the battery jumped to 13.25 v within 30 mins and then from there simply steadily charged till it got to about 13.97v

The power battery started at 12.66v and dropped to 12.26v for a total drop of .4 v. The charging battery went from 13.25v to 13.97v for a total gain of .72v

Now admittedly the batteries were new, and I didn't discharge the first battery before I put it on the system, so the readings are probably anomalous.

When I swap the batteries, I need to dishcarge the rest of the power battery before I can charge it, I'm assuming that discharging it to 12v is what I'm looking for before it's ready for charging again?

Since I didn't get over the 13.97 volts the other night, I hooked up my charger again.. this time the voltage jumped from 13.45v at the start and shot strait up to 15 volts. I don't want to overcharge or damage the battery so I'm assuming thats where I want to stop?

Reading some of the posts at pewski, there was a message from Bedini or bearden, they mentioned that what would happen is that the battery would peak and then drop slightly after it had been conditioned, basically achieving a steady platue of charging after that, slightly less than the peak. The battery reaching 15 volts so early seems unusual, how long should it take a battery to become conditioned in on this circuit?

[Ewhaz]

Messed up...

Drat.. I was using my charger, wondering why it was taking quite so long to charge.. Well I found out my circuit wasn't triggering properly. I tracked it down to the 555 and replaced it (damn glad I ordered extra) and now it seems to be oscillating properly. Now when the unit runs it has a chirping sound rather than the mosquito buzz. Hopefully It's working now. I'm having a hard time determining if the optocoupler is triggering properly but I do believe it's working for the simple fact that the coil is chirping. From previous experiments while I was assembling this thing, I know it would change pitch when the battery was hooked up on the charging side. If there weren't any connected, it would simply arc through the neon bulb I have there. The neon bulb now flashes, so I'm assuming this means the circuit is being interrupted between the battery and the capacitor.

Unfortunately my capacitors are overheating again, ARG! it's not as bad as it was before but definitely very warm to the touch.. I don't know why it's doing that though, I thought previously it was because the frequency is too high, now its at the right frequency but it's getting way too hot still. There's no such thing as a capacitor with a heat sink.

Update:

I Did a little research on temperature ranges for capacitors. It seems that the lowest I've seen them rated at is about 85 C (Or about 185F) and 105c is about the highest.

The pain threshold is between 54 to 55 C (About 130 F) so as long as it stays cool enough to touch without getting burned, the capacitor should be within it's operational range (Though with some loss to lifetime). However, its always better to be safe than sorry, always use caution when dealing with capacitors as they can explode.

[Aaron]

Bedini SG Dual Battery Charger

Dual Battery Charger

Here is the original schematic from about 7 years ago or so



Here is one my friend and I built virtually identical to every single spec on the drawing...they way John recommends starting out. Except we had the pulley a little bigger to let the caps get higher. It was the first time I think I ever tried to charge a battery with the SG's. You can see a folded piece of lead sheet on the left...that is wrapped around the battery I was charging in case it blew up.

[Aaron]

Bedini SG Bicycle Wheel Dual Battery Charger

Here was my original bicycle wheel setup:



I showed a zoom in pic at top left of my mechanical switch.... leads are alligator clips holding thin strips of copper sticking up. The pulley has another strip of copper taped to it and bent just right so that when it comes around counterclockwise, it will gently and evenly scrape both strips making the connection discharging the caps to the charging battery. I know a few people copied my switch and found that it worked great. When I used bigger batts and large cap banks, the exact switch worked perfectly. This is the discharge switch where I could charge for a while, turn everything off and the batt(s) would continue to charge for up to an hour with no more input.